Transferring liquefied gases



Patented Dec. 23, 1930 UNITED STATES PATENT OFFICE CHRISTIAN WILHEL M PAUL HEYLANDT, OF BERLIN-LANKWITZ, GERMANY Application filed February 9, 1929, Serial No.

The present invention relates to a process and apparatus for the utilization of the gases ordinarily lost and remaining during the emptying, filling and transferring of liqueflied gases of a low boiling point, said process having the distinctive feature that the liquefied industrial gases are transported to the place of consumption and there brought to the desired pressure by mechanical compres- 1 sion in order to avoid losses caused during transferring, while fully utilizing the inherent advantages of the transportation of liquefied gases. I

The process has furthermore the characteristic feature that the residual gases which are not brought by self compression to the desired working pressure at the place of consumption, are brought to high pressure by means of mechanical compression, for instance b compressors in order to avoid losses. inally, the subject matter of the invention is characterized by the fact that gases developing in the liquid containers during the gas consumption intervals and causing excess pressures, in said liquid containers, are brought to high pressures in the high pressure gas storage containers, by means of mechanical compression agents, as distinguished from self compression.

Liquefied gases of low boiling point such as, oxygen, nitrogen, hydrogen, methane, and the like,- used for industrial purposes, are usuall compressed into steel cylinders at the p ace of production and from there shippedto the places of consumption located at a distance, or they may be conducted there in pipe lines. Both of these methods of su ply are costly, because the average weig t of steel cylinders capable of taking only 0.5 kgs. of hydrogen or 8 kgs. of oxygen is 75 kgs., and of course the laying of pipe lines is expensive. The same conditions revail in connection with the shipping 0 other Fimilal 1:: z:

More vorable results areobtained, if the gases are first of all liquefied and then transported in liquid condition.

The. ther serv if the gases, conve ed to the place of consumption in liquefie condition,

puregose of economy will be still fur- 338,653, and in Germany February 16, 1828.

are compressed at the place of use in suitable devices, by self-compression, to the desired pressure, 1. e. under given circumstances up to 150 atm. and more.

In this connection difliculties however, are encountered inasmuch as in the, conveying of the liquefied gas from the vessel in which it is transported into the high pressure gasifier there are always certain unavoidable losses due to the transfer. Furthermore, the 00 present high pressure gasifiers together with the low temperatures occurring in the evaporation process and in particular in connection with the production of very high pres sures, do not meet the necessary requirements. Ihave found that these difliculties can be eliminated by bringing the gases, after transportation in liquid condition to the desired pressure at the place of consumption, by mechanical compression agents, whereby the advantages of transportation in liquefied condition are fully utilized while losses occurring during the transfer are almost entirely avoided.

The process in accordance with the invention therefore consists of the combination of processes partly alread known. The technical efiects, however, ring about a reduc tionin costs which is approximately equivalent to one half of the present production price. On account of the fact that gases, for instance the constituents of the coke furnace gases difiicult to bring to a boiling point, or oxygen and nitrogen, are used in liquid condition,-one can figure on a much greater shipping radius or zone with the same in vestment of capital as compared with the use of pipe lines or shipment in Steel cylinders.

The producer factories. can therefore be. maintained as large plants. The proven saving on account of this measure isabout 50 per cent of the present manufacturing costs. As a further advantage theremust be taken into account the considerable reduction of the costs in connection withshipments also for large distances. In the practiceof the resent invention, the shipp' costs are 0 y 15 per cent of the costs resulting from shipment of the gases in steel cylinders. A fu ther advantage is the delivery ot the liquefied gases to the consumer with absolutely no loss, for the reason that all evaporation losses during the emptying and transfer period and during operation are completely avoided by providing for the mechanical compression of such evaporation products. In this connection it is very important that the mechanical compression be carried out not at the place of production but at the place of consumption.

Finally the process can be carried out in such a manner that a part of the liquefied gas is carried directly from a low pressure tank to the place of consumption, by transferring into a high pressure tank for automatic gasification and high pressure compression, while the other part, i. e. the arising so-called waste gases, by means of mechanical compression work, are brought to such a high pressure as can only be obtained with great dilficulty by self-compression for practical. reasons.

In this manner, liquefied gases can be stored for quite long periods of time without any losses so that in a time of non-consump-- ticn the resulting evaporation products are brought continuously, by mechanical compression means, into suitable pressure containers at the place of consumption, in this way avoiding a loss of gas to the outside.

The expenditure of work for such a compressor which in such event has to compress gas of about ats. to 150 ats. is very small. In connection with about 100 cubic meters per hour, it is only about 2 H. P. In the latter case, the revolving compressor is arranged at the place of consumption.

In the drawings accompanying this specification,

Fig. 1 is a partly sectional diagrammatic side view of an apparatus adapted to carry out the process herein described; and

Fig. 2 is a similar side view illustrating a modified form of the apparatus.

In Fig. 1 of the drawing, 1 designates a vessel adapted to contain liquefied gases, said vessel being mounted on a motor truck 1*. On the truck is also'mounted a compressor 2, which may be Operated by the truck motor. Communicating with said com ressor are a pair of pipe lines 3 and 7, w ich may be formed of pressure hose and provided with connections 4 and 8 respectively. At the place of consumption is constructed a chamber 11 in which is disposed a gasifier 20, having a filling tube 21 communicating with a liquid conveyor line 22 which communicates with the outlet from the transporting vessel 1. The gasifier 20 is also provided with a gas outlet pipe line 12 havin a valve 6 for controlling the flow of gas therefrom, said pipe line having a branch 12 which communicates with the main pipe I2 at a point between the valve 6 and the vessel 20, said branch being provided with a valve 5 and having a connection at its free end adapted to be coupled with the connection 4 of the pipe 3. Also disposed at the place of consumption are a plurality of steel cylinders 10, each in communication with a pipe line 23 provided with a valve 9 and having at its free end a connection adapted to be coupled with the connection 8 of the pipe line 7.

With the apparatus above described, the storage and supply cylinders 10 may be charged with gas at a given high pressure by transferring the substance in the liquid condition from transport vessel 1 to the vessel 20 in chamber 11. After transfer to the latter vessel, the liquid is allowed to warm up and vaporize, thus producing a high pressure, and upon opening the valve 6 the gas flows into and charges the cylinders to the required pressure. Afterall. the pressure gas has passed from the vessel 20, the valve 6 is closed and valves 5 and 9 opened, whereupon the residue of gas remaining in the Vessel 20 which is at a ressure below that of cylinders 10, may be rawn off by the pump 2 and forced into the cylinders at the required pressure. This operation takes place prior to the introduction of a fresh charge of liquid into the vessel 20. In this manner, the gas remaining in vessel 20 after each operation, instead of being lost as heretofore, is compressed mechanically and may be forced into one of the steel c linders 10 or into a lowpressure receptac e ready for consumption when required.

In the modification illustrated in Fig. 2, the liquefied gas container l is shown mounted on the truck 1, together with the compressor 2 and a plurality of pressure vessels 16. The compressor in this instance is placed in communication with the upper portion of the liquefied gas container and with the pipe 3 by means of a pipe 13 provided with a valve 17, in addition to the pipe lines 3 and 7 hereinbefore described for communication with the vaporizer and the stationary pressure tanks 10. The valves 5 and 9, as well as the pipe connections 4 and 8 carried by the pipes 3 and 7 are in this instance disposed at the outer ends of said pipes, the tanks 16 communicating with the pipe line 7 by Way of a pipe 15 provided with a valve 14. By reason of this construction, the compressed gas can be supplied directly from the truck to the consumer.

Having thus described and ascertained the nature of my said invention, what I claim is:

1. The process of supplying gases at a predetermined pressure, which consists in charging a closed vessel with liquefied gas, vaporizing' the liquid in said vessel and causin the major portlon of the gas to flow there rom at the desired pressure, and mechanically izing the liquid in said vessel and causing themajor portion of the gas to be self-compressed and to flow from said vessel at the required pressure, and pumping the residue from said vessel and forcing it at the desired pressure into a pressure container. r

3. Apparatus for supplying gases at predetermined pressures, comprising in co ination, a portable liquefied-gas container, :1. portable compressor, a vaporizing vessel, means for establishing communication between said container and vessel for delivering liquefied gas to the latter thereby to vaporize said gas, means for automatically delivering the major portion of said vaporized gas at the desired pressure, and communicating means between said compressor and vaporizing vessel for withdrawing the residue. from said vessel and compressing said residue.

In testimony whereof Lhave signed my name to this specification.

CHRISTIAN WlLHl-ILI PAUL HEYLANDT. 

